Youre organizing the First Annual 72-Hour Dance Exchange, to be held all day Friday, Saturday, and Sunday. Several 30-minute sets of music will be played during the event, and a large number of DJs have applied to perform. You need to hire DJs according to the following constraints.

Exactly k sets of music must be played each day, and thus 3k sets altogether.

Each set must be played by a single DJ in a consistent music genre (ambient, bubblegum, dubstep, horrorcore, hyphy, trip-hop, J-pop, swing, Nashville country, . . . ).

Each genre must be played at most once per day.

Each candidate DJ has given you a list of genres they are willing to play.

Each DJ can play at most three sets during the entire event. Suppose there are n candidate DJs and g different musical genres available.

Describe and analyze an efficient algorithm that either assigns a DJ and a genre to each of the 3k sets, or correctly reports that no such assignment is possible.